In reality Blake is the essential British artist. He is the only one we have ever produced who really captures the national genius. This is because he was a writer as well as an artist – and the English language is Britain's true cultural achievement. We are not, repeat not, a nation of artists. The lack of great artists in our history is hilarious when you set it aside most other European nations. We have no Titian, Rembrandt or Picasso. We don't even have a Dali. But we do have William Blake.

It is the conceptual quality of Blake's art that raises it above the run of British visual achievement. In a work such as The Marriage of Heaven and Hell, his illumination of his own words is like a fire of free throught blazing on the paper. In his sweet decorations for his Songs of Innocence and Experience we glimpse the lineaments of a lost folk art. In the powerful and intense hand-coloured prints now purchased by Tate, we see how real colouristic brilliance, as well as a magnificent graphic boldness, enabled Blake to impose his unique vision on history. Blake walked among angels and saw with their eyes. His rapturous mind lives on through these magnificent works. What a gain for the nation.